package com.xp.flower.qsd.utils;

import java.security.MessageDigest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;



public class MD5Util 
{
	
	private final static Logger logger = LoggerFactory.getLogger(MD5Util.class);

	private static String byteArrayToHexString(byte b[]) 
	{
		StringBuffer resultSb = new StringBuffer();
		
		for (int i = 0; i < b.length; i++)
		{
			resultSb.append(byteToHexString(b[i]));
		}

		return resultSb.toString();
	}

	private static String byteToHexString(byte b) 
	{
		int n = b;
		
		if (n < 0)
		{
			n += 256;
		}
		
		int d1 = n / 16;
		int d2 = n % 16;
		
		return hexDigits[d1] + hexDigits[d2];
	}

	public static String MD5Encode(String origin, String charsetname) 
	{
		String resultString = null;
		
		try 
		{
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			
			if (charsetname == null || "".equals(charsetname))
			{
				resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
			}
			else
			{
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
			}
		} 
		catch (Exception e) 
		{
			logger.error("微信支付MD5加密失败： " + e.getMessage());
		}
		
		return resultString;
	}

	private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

}

